velocity question ???

[Walks with fire]

I have noticed that TC load charts indicate that a 230 grain .530 patched ball will reach 1855 fps. with a 100 grain charge of 2F powder.

The same manual shows a 240 grain PA Hunter .50 caliber ball-et conical reaching only 1650 fps. with a 100 grain charge of 2F.

My question is; why is there so much diffence in velociy with these loads? I do understand that there is less bearing surface with the patched .54 caliber ball and the .50 conical weight is 10 grains heavier but it does seem that the conical load is pretty slow. Anyone care to comment?

 

[hanshi]

I ignore velocity and just try for the most accurate load.

 

[russecv58]

I ignore velocity and just try for the most accurate load.

What he said :thumbsup:

 

[CoyoteJoe]

Well, just to confuse the issue even more, the Lyman BP Handbook, 2nd edition, lists a .535" ball from a 28" barrel with 48" twist, basically like a T/C barrel. They list 100 grains of Goex 2f as producing 1592 fps and 100 of 3f going 1683.
Now for the same barrel with the lightest conical they list, the 338 grain Ball-et, 100 grains 2f gave 1537 fps, they didn't test 3f with that bullet.
I haven't a clue as to why data should differ so much from two reputable sources but there it is. :idunno:

 

[jtmattison]

I ignore velocity and just try for the most accurate load.

What he said :thumbsup:

X3

HD

 

[necchi]

I ignore velocity and just try for the most accurate load.

What he said :thumbsup:

X3

HD

X4.

I load for CF also, with those the velocity is/can be a factor in a desirable load.
With Traditional ML stuff and the effective range of such and the words "rainbow trajectory" pretty much negates a 200fps variation.

As too why they have the variable?? Who knows ?? Something as simple as how hard the loader packs the final load or the weather conditions that day can lead to a variation.

 

[CoyoteJoe]

Oh wait, I had assumed you were comparing round ball to conical of the same caliber. Now I realize you are comparing a .54 ball to a .50 conical of similar weight, that explains a lot. A bigger bore in a gun is just like a bigger bore in an internal combustion engine, it provides a larger piston area on which the pressure operates. More power from a given pressure. Such comparisons will naturally be quite different.

 

[roundball]

I have noticed that TC load charts indicate that a 230 grain .530 patched ball will reach 1855 fps. with a 100 grain charge of 2F powder.

The same manual shows a 240 grain PA Hunter .50 caliber ball-et conical reaching only 1650 fps. with a 100 grain charge of 2F.

My question is; why is there so much diffence in velociy with these loads? I do understand that there is less bearing surface with the patched .54 caliber ball and the .50 conical weight is 10 grains heavier but it does seem that the conical load is pretty slow. Anyone care to comment?

Hard to say...its always difficult to compare apples and oranges...ie: a .54cal something to a .50cal something, and then different projectiles at that.

Pure speculation on my part...but "way back when" as TC developed its load data charts (1970s) and published those initial figures...ie: the .54cal, I don't think they've updated the old chart data since then.
And they may have been kind to themselves in their posted velocities because I've chronographed their PRB loads in both 28" and 32" T/C barrels, in .45/.50/.54cals...and never got the high velocities that they claim.

Fast forward 30 years and if they've now added a .50cal ball-et to their data charts, they may now be taking a "more accurate approach" to the velocity listings...but don't know of course.
Bottom line I think its almost impossible to compare apples and oranges regardless...

 

[Zonie]

I think your mixing apples and oranges.
Although the weights of the projectiles you mention are fairly close the calibers are different.

A 100 grain powder load will generate significantly different velocities when used in a .50 caliber and a .54 caliber gun.

I also think that the velocities that Thompson Centers prints in their guide book are more than optimistic.

I'm not saying TC made them up but I don't doubt that they printed the very highest test reading their velocity tests registered rather than printing the average velocity of the load.

While I know there are a few places where the Lyman Blackpowder Handbook has some obviously incorrect data, for the most part their test results seem logical and I tend to believe them.
After all, unlike TC, Lyman didn't have a dog in the fight.

 

[gordy]

I would have to agree , accy. to me is more important than Max. velosity.
:thumbsup:

 

[Lonegun1894]

I would have to agree , accy. to me is more important than Max. velosity.
:thumbsup:

Couldn't agree more, especially when you consider that usually the best accuracy is NOT achieved at the maximum velocities. Accuracy is the main concern, as a couple hundred feet per second either way wont make any difference if your accuracy isn't up to what you need.

 

[Rifleman1776]

I ignore velocity and just try for the most accurate load.

I'm going to have to start getting up earlier than Hanshi. As usual, he nailed it.
In the bp/ml game don't get hung up on numbers. Velocities, energies and such just do not translate into real world effectivness like the do in the modern gun world. And fretting over them takes away most of the fun.

 

[CoyoteJoe]

Numbers don't translate to effectiveness in modern guns either but velocity does affect bullet drop for ML or modern, and some of us enjoy playing the numbers game.

 

[longcruise]

There are many "reputabble" sources of this type of information, and they are indeed reputable. But,.. If you ever play around with your loads and a chrono you will soon find that there are so many variables that effect velocity with ml guns that the only way to get accurtate data is to shoot it yourself. It's the same with the modern stuff. Rarely does a reloading recipe produce the same results in your rifle as was listed in the manual.

Like others have said though, it's not really that important. Any reasonble velocity and load will take game. For accuracy, it speaks for itself and velocity is mostly unimportant to paper punching.

So, either get a chrono and experiment or ignore it completely and just apply common sense. Whichever you prefer.

 

[BrownBear]

I agree. The only place you might notice even 100-200fps differences is in trajectory at longer ranges, and there won't be that much either unless you go to swapping calibers.

Then there's the fact of differences between individual guns with all else being equal. It's a modern example, but I'm the proud owner of three Ruger Redhawks sequentially serial numbered from the first year of production. Identical in every way and they followed each other off the assembly line. And with the same load there's close to a 100 fps spread between the fastest and slowest. Go figure. It wouldn't surprise me in the least to see the same from three muzzleloaders following each other off the assembly line.

 

[zimmerstutzen]

I have never been very concerned with velocity in a gun. I want an accurate load with pleasant recoil.

Almost every one will obtain different velocities even from the same model and caliber of gun,. due to a number of other factors. lube, load tightness, etc.

A 54 caliber gun has one advantage over the 50 that no one has mentioned yet. The 54 bore can burn 100 grains in a shorter length of barrel than a 50. Larger diameter for the powder to burn in. AND the initial load, takes up less length of bore because the 54 is larger in diameter. I never measured how much 50 caliber bore would be occupied by a 100 grain load, but a 100 grains in a 54 caliber bore would take up less bore length, by about 14%. (comparing the volume of a inch of 50 cal bore to the volume of an inch of 54 caliber bore the 54 caliber bore volume is 14% larger) Not only does the larger bore permit the powder to be consumed in less length, there is more initial length of bore for the 54 caliber bullet to travel before exiting the muzzle.

 

[Walks with fire]

Well thanks for all the replies. I am not a velocity nut either it's just that I didn't feel there should be that much difference or that I just didn't understand why it was that different.

I look for an accurate and reasonable recoil load. I like the .50 because it's the most common caliber in todays world. I work on placement and don't push the distance with my shots. 80-90 grains of 2f shoot best in my roundball gun and it's a comfortable recoil with some good power. I go to a conical bullet and not more powder if I want more range. I accept the trajectory.

 

[Io]

The slippery drag of a patch and the solid contact of the conical or unpatched ball are sure to make some differences in drag that could explain it, as too could the grainweight add to the differences.

I'd follow the thoughts of others here and shoot for accuracy and take the speed you get as a bonus for the x ring..

 

[Io]

Boy, now you really got into the weeds... :grin:

I was always curious why a 50 would do better than my 45's even though they both were of the same bullet weight and your right. The increased surface area the blast has to work on with a larger bore seems to be one of the main ingredients, the shorter powder column for sure allows energy to be effective more quickly and I've heard it said that the shorter bullet has less linear drag, though I'm still wondering out loud, and maybe I shouldn't be too loudly, what about the larger surface area of the bigger bore...

 

[Herb]

TC's velocity with that .530 patched ball is an aberration. I chronograph a lot of loads and in three .54's, a 32" Hawken I built, a 34.5" Leman ditto and a 36" Hawken, these are the averages I got, usually five shots: 1577 fps, 1662, 1691, 1670, 1637, 1658 and 1735. There are different patches involved here, but all .530 balls and Goex 2F. I have not shot the PA Hunter ball-ets and know nothing about them.